Optical properties of long-range transported volcanic ash over Romania and Poland during Eyjafjallajökull eruption in 2010

• Published in: Acta Geophysica
• Main Authors: Nemuc, Anca, Stachlewska, Iwona, Vasilescu, Jeni, Górska, Anna, Nicolae, Doina, Talianu, Camelia
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Walter de Gruyter GmbH 2014
• Subjects: Geophysics; Eyjafjallajökull
• Online Access: http://dx.doi.org/10.2478/s11600-013-0180-7

Abstract After Eyjafjallajökull volcano eruption on 14 April 2010, due to a complex air mass circulation, Romania was exposed to volcanic ash and its mixture with continental aerosols. Ash particles with an average Ångström (UV-VIS) exponent of 1.4 ± 0.2 and (VIS-IR) of 1.2 ± 0.3, a color ratio (VIS-UV) of 0.54 and (IR-VIS) of 0.49, an average particle depolarization value ∼9.4%, and a lidar ratio of 50 sr were retrieved on 18 April from multiwavelength Raman lidar measurements in Bucharest. Mixed volcanic ash with mineral dust particles advected from Sahara, depolarization ∼12%, Ångström (UV-VIS) exponent of 1.25 ± 0.25 and (VIS-IR) of 1.45 ± 0.25, an increased color ratio (VIS-UV) of 0.61, (IRVIS) of 0.39 and lidar ratio of 53 sr were identified on 28 April. From observations in Poland conducted by an elastic lidar at 532 nm and a ceilometer at 1064 nm we retrieved an average backscatter related Ångström (VIS-IR) exponent of 1.25 ± 0.35, and a color ratio (IR-VIS) of 0.53 in the layer at about 5.5 km during the night of 16/17 April, indicating fresh ash over Warsaw.